Fluid dispensing apparatus



July 15, 1969 P. CRIPPEN ET AL 3,455,486

' FLUID DISPENSING APPARATUS Filed Sept. 7, 1967 INVENTORS PE TE I? CR/PPE N ARTHUR JAMES EVANS United States Patent Oflice 3,455,486 Patented July 15, 1969 3,455,486 FLUID DISPENSING APPARATUS Peter Crippen, Banstead, and Arthur James Evans, Stoke DAbernon, England, assignors, by mesne assignments, to The Distillers Company (Carbon Dioxide) Limited, Reigate, England, a British company Filed Sept. 7, 1967, Ser. No. 666,037 Claims priority, application Great Britain, Sept. 16, 1966, 41,585/ 66 Int. Cl. B67d 5/08 US. Cl. 222-61 5 Claims ABSTRACT OF THE DISCLOSURE Apparatus for dispensing beer and similar liquids comprising a diaphragm pump and various switches and valves to ensure the delivery of measured quantities of the beer or liquid as required.

This invention relates to dispensing apparatus, more particularly to apparatus for the dispensing of liquids including carbonated liquids, for example, beer.

It is already known to dispense liquids, by means which include piston-operated or diaphragm pumps.

It is an object of the present invention to provide apparatus for dispensing liquids which provides various improvements over that already known.

Accordingly, the present invention provides apparatus for dispensing a liquid, hereinafter called beer, which comprises a diaphragm pump, fitted with (a) a beer supply pipe having a beer inlet non-return valve and a flow-operated electromagnetic switch,

(b) a beer dispensing pipe having a non-return outlet valve, a beer dispensing valve and a dispensing control device,

(c) a pipe for supplying a fluid, hereinafter referred to as air to operate the diaphragm having a high speed exhaust valve and an air control valve,

and circuitry connecting the switches and valves, in such a way that when the pump is full of beer and the dispensing control switch is operated, a pre-determined volume of beer is dispensed.

The diaphragm pump used in the apparatus of this invention comprises two dished plates with a free-moving diaphragm between them. It is preferably designed so that the part which receives the beer is the upper part and is provided with a common inlet and outlet port for the beer while the part which receives the air is the lower part. This is preferably also provided with a single port through which the air can be introduced to exert pressure on the diaphragm and expel the beer. This port can also be used for the discharge of the air from the pump after the beer discharge stroke. If desired, however, a second port could be provided for this purpose and this could also be controlled by means of, for instance, a solenoid valve. It has been found that if the neck of the common inlet and outlet port is widened so that its diameter is greater than that of the beer dispensing pipe a better response is obtained at the end of the dispensing cycle, when the pre-determined quantity of beer has been displaced from the pump. To assist this quick shut off from the constant velocity condition that exists during the beer discharge stroke the diaphragm is provided with a pad or thickened portion at that part of it which corresponds with the widened neck. This is a preferred feature of the invention. If desired a preformed volumetric adjustment device can be secured to the bottom diaphragm plate or to the underside of the diaphragm.

The material used for the construction of the dished plates may be of ferrous or non-ferrous type, for example aluminium. The surfaces in contact with the beer or liquid being dispensed are suitably coated with an epoxy resin or nickel tin plating. Plastic diaphragm plates may also be used.

The flow-operated switch in the beer supply pipe may be any device which will actuate an electrical circuit when the rate of flow of beer through it reaches a certain value. A preferred device comprises a valve body of nonmagnetic material through which the beer can pass, at least one magnetic reed switch mounted adjacent to the valve body and a non-return valve with a magnetic core which actuates the switch when the valve is adjacent to it. The valve is, however, responsive to the flow of beer through the chamber, and when it is thereby caused to move away from the switch the circuit is broken.

When the flow-operated switch is combined with the beer inlet valve to form a single valve/switch and the valve is at rest on the valve-seating it acts as a seal to stop the flow of beer. The valve seating is adjacent to the magnetic reed so that when acting as a seal the magnet in the valve acts on the switch and closes the circuit. The size and configuration of the combined valve/switch is such as to enable rapid refilling of the pump to take place. The clearances between the valve and the valve body directly affect the cut-off rate of the valve and the response time of the electric or other circuitry. This combined valve/ switch is relatively inexpensive and reduces the complexity of the apparatus.

In a preferred embodiment, the beer inlet valve, the flow-operated switch and the beer outlet valve may all be incorporated into a unitary inlet/outlet valve box. The beer-dispensing valve may be manually, pneumatically, electrically or electro-magnetically operated. Conveniently an electrically responsive valve for example a solenoid valve can be used.

The dispensing control device is located at the bar or other convenient location and can be manual, electrical or pneumatic. Preferably it is a press button switch which on pressing closes an electric circuit.

The beer" supply pipe has preferably a wide bore for example 'inch internal diameter to permit rapid filling of the pump after each cycle. It can be fitted if desired with a branch connection for cleaning purposes.

The beer dispensing pipe, however, is preferably of narrow bore for example inch internal diameter. This provides a high rate of flow through the pipe which means that on completion of the pump stroke there will be sufficient reduction in pressure to actuate the flow-operated switch in the beer supply pipe. The high rate of flow ensures self cleansing of the pipe and the avoidance of the collecting of sediment in the apparatus.

If desired an adjustable control device can be provided at the entry to the beer dispensing valve, which enables highly carbonated beers to be dispensed without excessive fobbing occurring at the point of discharge. The valve may include the actual dispensing point or tap and can also incorporate a sparkler device.

The air control valve may be electro-magnetic or pneumatic.

The high speed exhaust valve may be incorporated in the air control valve for instance as a three-way solenoidoperated valve which when open supplies air to the pump, but when closed cuts off the air and provides a vent to the atmosphere for the air in the pump. It is preferred, however, to have a high speed exhaust valve close to the air inlet of the pump in order to remove air from the pump chamber in the quickest possible time, thereby ensuring rapid refilling of the pump with beer. A convenient high speed exhaust valve depends on pressure differences in the pipe and only operates when such a difference exists,

i.e., in the apparatus of the invention when the air flow is cut off.

The apparatus of the present invention will now be described with reference to a particular embodiment thereof as shown in the accompanying drawings in which:

FIGURE 1 is a representation of beer dispensing apparatus according to the invention employing air as the operating fluid.

FIGURE 2 is the electrical circuitry required by the apparatus shown in FIGURE 1.

FIGURE 1 shows a diaphragm pump 1 consisting of two dished members 2 and 3 bolted together to form a dispensing chamber 4 across which is positioned a flexible diaphragm 5 fitted with a pad 6. The position of the diaphragm and pad after sweeping the chamber 4 is shown by the broken line 7. Air is fed under pressure to the chamber4 via a solenoid valve 8, pipe 9, high speed exhauster valve and finally through port 11. Beer under a pressure of about 2-5 p.s.i. is fed to the chamber 4 from the tank 12 through pipe 13 to the combined switch/valve 14. The pressure on the beer in the tank is maintained through pipe 27 using carbon dioxide as the head pressure medium, through pipe 15 and finally into the chamber 4 through a common inlet and outlet port 16, the neck of which is flared so as to correspond with the pad 6 of the diaphragm 5. Switch valve 14 is arranged such that when in closed position it completes the circuit and when acted upon by a differential pressure lifts and so breaks the circuit. Beer leaves the pump chamber through inlet and outlet port 16, through pipe 15, through non-return valve 17, through pipe 18, through solenoid valve 19 and finally to dispense point 20. All the pipes are of narrow bore tubing so that they are self-cleansing.

FIGURE 2 shows the circuit diagram which in addition to the electrical features referred to above also shows a push button switch 21, a relay 22 and a 240 v./25 v. transformer 23. The circuit also includes an optional dispense cycle counter 24 and an optional continuous cycling switch 25 which could be used for cleaning out the whole system.

Before a dispensing cycle is initiated the dispensing chamber 4 is full of beer, the flexible diaphragm being in position 5, solenoid valves 8 and 19- are closed and valve/switch 14 is in the closed position, i.e. the valve is closed and the circuit is complete. A dispensing cycle is initiated by depressing push button switch 21 which energises relay 22 which in turn energises solenoid valves 8 and 19 causing them to take up an open position. This permits air to flow under pressure past solenoid valve 8 through pipe 9 and port 11, and act upon the flexible diaphragm 5 forcing the beer from the chamber 4 through port 16 along pipe 15 past non-return valve 17 along pipe 18 past solenoid valve 19 to dispense point 20. When the flexible diaphragm reaches position 7 the predetermined level or quantity of beer has been expelled from the chamber 4 and the beer flow in pipe 15 ceases while the flow in narrow bore pipe 18 momentarily continues which causes the valve in switch valve 14 to be lifted thereby breaking the circuit, de-energising the relay 22 which in turn closes solenoid valves 8 and 19. The small volume of the valve body, however minimises degassing. The closin of solenoid valve 8 causes high speed exhauster 10 to vent the air present in chamber 4 to the atmosphere and at the same time beer enters the chamber through the open valve/switch 14. The flow of beer through the valve/ switch maintains it in an open position thus ensuring that a further dispense cycle is not initiated until the dispensing chamber 4 is completely filled with beer. As soon as the chamber is full of beer the flow across the valve/ switch 14 ceases and the valve reverts to its closed position closing the valve and completing the circuit. The apparatus is now ready for a further dispensing cycle which can be initiated by depressing push button switch 21.

Depending on the variables of the site on which the apparatus of the present invention is installed, on the nature of the liquid to be dispensed, on the flow characteris ics of the apparatus and on the nature of the response obtained from the valve/switch, various refinements and adjustments to the apparatus can be made for example by the installation of time delay devices and flow speed regulators.

To dispense a given volume of beer the volume of the dispensing chamber of a diaphragm pump has to be ad justed accordingly. In the past this has been achieved by producing a pump chamber which is approximately the required volume and adjusting the volume accurately by the insertion of shims between the bolted plates of the diaphragm pump. This method is generally unsatisfactory in that the chambercan be tampered with and to avoid this the unit has to be completely sealed. We have now found a simple means for adjusting the dispensing volume of a diaphragm pump avoiding these disadvantages. This comprises a volume control disc which corresponds with or can take up the inner surface shape of the operating side of a diaphragm pump. This disc is perforated with a plurality of concentric rings and provided with a central hole to permit passage of operating fluid therethrough, whereby the dispensing volume of the diaphragm pump is altered by adjusting the extent of the stroke of the diaphragm by removing the appropriate number of concentric rings from the disc. Preferably the disc is provided with an adhesive which bonds the disc to the operating inner surface of the diaphragm pump. Such a disc can be made from a thin plastic sheet for example. If by chance too many concentric rings are removed it is a simple matter to replace the disc and start afresh. This type of volume control is not susceptible to tampering in that an ofiicial can check the number of concentric rings removed from a standard disc, stamp the outside of the pump accordingly and thus avoid the tiresome and expensive business of oflicially sealing the pump unit. Such a volume control disc is ideally suited for the apparatus according to the present invention and is a preferred feature thereof.

Some advantages of the apparatus of the present invention are:

(1) The flow-operated switch prevents a dispensing cycle being initiated whilst the diaphragm pump is being filled with beer. This is because beer enters the pump under its own pressure via the flow-operated switch, thus causing a differential pressure across the switch by virtue of the flow of beer and thereby maintaining the switch in an open position until the pump is full whereupon the valve drops to its closed position completing the circuit and enabling a further cycle to be initiated.

(2) When repeatedly dispensing fixed quantities of liquid the actual variation in quantity is of the order of 1% which is much lower than that achieved by previous diaphragm dispensing pumps and is acceptable to the appropriate authorities.

(3) The diaphragm movement allows for operation at low pressures with good efiiciency.

(4) In the case of carbonated liquids, e.g. beer, the whole system can be maintained at a pressure such that gassing is virtually eliminated and the quality of the liquid, particularly that present in the system is not impaired. The apparatus is also suitable for highly carbonated beers e.g.

v lagers at pressures up to about 25 p.s.i.

(5) Narrow bore tubing is used and thus the apparatus is self-cleansing.

(6) Dripping from the dispense point is substantially eliminated.

(7) There are no moving rods attached to the diaphragm.

(8) The valve/ switch unit which controls the dispensing operations does not need to be adjacent to the pump.

(9) The system is capable of dispensing fluids of all degrees of carbonation and the free moving diaphragm and the large capacity gravity operated inlet valve ensure rapid refill rates.

5 We claim: 1. Apparatus for dispensing a liquid which comprises a diaphragm pump, fitted with (a) a liquid supply pipe having a liquid inlet nonreturn valve and a flow-operated electro-magnetic switch,

(b) a liquid dispensing pipe having a non-return outlet valve, a liquid dispensing valve and a dispensing control device which includes a switch,

(c) a pipe for supplying a fluid to operate the diaphragm, having a high speed exhaust valve and an electrically operated fluid control valve and circuitry connecting the switches and valves, whereby when the pump is full of liquid and the dispensing control device is operated, the circuit is closed, causing the fluid supply valve and the liquid dispensing valve to open, and the liquid inlet valve and the fluid exhaust valve to close, whereupon fluid flows into the pump and drives liquid out through the dispensing valve until the pump is empty of liquid, whereupon the liquid inlet valve opens under the pressure of the liquid in the supply pipe, and the resulting flow of liquid operates the electro-magnetic switch, thus breaking the circuit and causing the fluid exhaust valve to open and the liquid dispensing valve and the fluid supply valve to close, allowing liquid to flow into and refill the pump, thus readying it for a further dispensing cycle.

2. Apparatus as claimed in claim 1 wherein the diaphragm pump has a common inlet and outlet valve for the beer.

3. Apparatus as claimed in claim 1, wherein the outlet port of the pump is of greater diameter than the beer dispensing pipe and the diaphragm has a pad or thickened portion at that part of it which corresponds with the port.

4. Apparatus as claimed in claim 1 wherein the flowoperated electrical switch is a magnetic reed switch.

5. Apparatus as claimed in claim 1 wherein the flowoperated switch is combined with the beer inlet valve to form an integral valve/ switch.

References Cited UNITED STATES PATENTS 2,388,662 1l/l945 Anderson et al. 222334 X 3,216,627 11/1965 Best et al. 222-334 X 3,220,608 11/1965 Porter 222334 X 3,227,314 1/1966 Porter et al. 222334 X ROBERT B. REEVES, Primary Examiner H. 5. LANE, Assistant Examiner US. Cl. X.R. 22276, 334 

